...IRS data show far fewer agency audits aimed at large corporations providing investment advice, various kinds of banking and credit services and insurance than to corporations in other businesses. The big disparities -- documented in previously undisclosed data obtained and analyzed by TRAC -- concern corporations with $250 million or more in assets. The new IRS data document that on an overall basis only about one in three were audited. Other data show that despite recent IRS claims that it is vigorously enforcing the tax laws, the audit rate for all corporations has continued to decline along with the face-to-face audits of wealthy taxpayers.